The present invention relates to a harness arrangement structure of a vehicle.
Hybrid vehicles or electric automotive vehicles, which are equipped with a motor for driving vehicle, have been recently popular. In this case, a high-voltage battery is installed in addition to a normal low-voltage battery. An electric supply from the high-voltage battery to the motor is controlled by a main relay, and this main relay (its relay coil) is activated by the low-voltage battery as an electric source.
A switch means is provided in a feeder circuit for the main relay in order to cut the electric supply from the high-voltage battery to the motor by making the main relay OFF when an abnormal situation, such as a vehicle collision, happens. This switch means is generally comprised of a semiconductor element (switching transistor), and a p-type of semiconductor element has been used popularly. More specifically, the above-described switch means is provided between the main relay and the low-voltage battery in the circuit. US Patent Application Publication No. 2011/0088944 A1 discloses a protection structure of a harness connecting a high-voltage battery to an inverter which is arranged below a floor panel. This publication, however, discloses nothing, in particular, about cutting or electrically grounding of a feeder circuit for the main relay.
Meanwhile, it may be considered that the switch means which is provided to make the main relay OFF is disposed between the main relay and the vehicle-body ground. It may be considered that an n-type of semiconductor element which is advantageous in costs, stability and the like is used as the switch means. In this case, the feeder circuit for the main relay is constituted at least by the first harness, the main relay, the second harness and the switch means which are connected in series from the low-voltage battery to the vehicle-body ground side.
Herein, there may occur a case in which the above-described second harness is damaged (or cut in a radical case) in the vehicle collision or the like. Especially, since the main relay is generally arranged outside the vehicle similarly to the high-voltage battery, part of the second harness is located outside the vehicle. Accordingly, there is a possibility that the second harness may be damaged.
In the case in which the switch means is provided on the vehicle-body ground side from the main relay as described above, when the second harness is merely damaged simply, the electric supply to the main relay is cut by opening the switch means (OFF), so that the electric supply from the high-voltage battery is cut. However, when the second harness is damaged and electrically grounded to a vehicle body, the main relay keeps its electric supply state even if the switch means is opened, so that the electric supply from the high-voltage battery may not be cut.